In a mine, ground support, e.g. rock bolts and screening, is used to prevent rock falls. Several different types of rock bolts may be used but all require that holes be drilled in the rock first. This is done with equipment known as rock drills or combined drilling-bolting systems. These are typically mobile units with a bolting head attached. To drill a hole in the rock to install ground support, the bolting head is placed against the rock face (which is called “stinging the face”) and then a hole is drilled into the rock. The unit is then indexed to install the rock bolt as ground support.
Conventionally, rock drilling systems employ centralizer assemblies composed of many rigid metal components, which are prone to vibration and which increase the weight of the assembly. These include rigid metal stinger bases, centralizer bases and tops, steel centralizer bushings. The metal components transmit unwanted vibrations from the drill steel to the feed assembly, causing wear and loosening of components.
In view of these shortcomings of the prior art, an improved rock drilling system remains highly desirable.